Sealed package and method of making same



Jan. 14, 1941. M. H. SMITH ETAL SEALED PACKAGE AND METHOD OF MAKING SAMEFiled March 1, 1939 f] gave/250m: u/al! 'fi Fe 21. M54 W W M my PatentedJan. 14, 1941 UNITED STATES 2,228,785 PATENT OFFICE SEALED PACKAGE ANDMETHOD OF MAK- ING SAME Marshall B. Smith, Neenah, Wis., and Roy A.Nash, Bronxville, N. Y., assignors to Marathon Paper Mills Company,Rothschild, Wis., a corporation of Wisconsin Application March 1,

8 Claims.

This invention relates to the sealing of articles which have beenwrapped in sheet materials. More specifically, this invention relates tothe wrapping of bread in sheet materials such as paper, waxed paper,Cellophane (regenerated cellulose), Glassine, parchment paper, celluloseacetate and the like, and sealing the ends of the overlapped portions ofthe wrapper with a seal which is secured by heat and pressure. Thisinvention also relates to the application of seals, bands, and the like,to a paper package and to any desired portion of said package.

At the present time, a large number of food items, particularly bread,are wrapped in waxed paper. It is the practice to overlap the endportions of the wrapper, particularly at the ends of the wrapper, andseal the seams by heat and pressure. It has been found that the strengthof the seal so formed is comparatively weak and can be readily opened bya slight pulling force. Furthermore, the seal thus produced does notinsure perfect sealing of the contents. A similar difficulty arises inthe packaging of cartons and other similar articles in an outer wrapperof waxed paper and the like for moisture-proofing and protecting thecontents within the carton. Considerable difiiculty has been encounteredin properly sealing the overlapped portionof the outer waxed wrapper, soas to insure a perfect seal for the contents of the package.

The object of this invention, accordingly, is to overcome the abovementioned diificulty by providing sealing means for the ends of wrapperson bread loaves, cartons containing contents which are to be protectedagainst moisture or loss of moisture, and any other commodities whichare wrapped in waxed paper, inorder to protect same againstdeterioration or spoiling by loss of moisture or entrance of moisture.

Further details of the invention will appear from the followingspecification and the appended drawing wherein Figure l is a perspectiveview of a loaf of bread wrapped in waxed paper having the ends thereofsealed in accordance with the invention,

Figure 2 is a perspective view of the sealing label,

Figure 3 is an exploded fragmentary perspective view of the breadpackage and the end seal label,

taken on lines 4-4 of Figure 3, and

Figure 5 is a fragmental perspective view of the sealed package showingthe end seal partially peeled therefrom.

According to the present invention, the article such as a loaf of breadis wrapped in a wrapper of ordinary waxed paper 20. The overlapped endsof the package, 2|, as shown in Figure 1, are pressed together andadhered by means of the Figure 4 is an enlarged cross-sectional view1939, Serial No. 259,248

coating of wax M or wax-like composition, which is present upon thesurface of the wrapper 20. The adhesion of this bond provided by thewax, or wax-like coating upon the wrapper 20 is ordinarily not verystrong. Furthermore, the overlapped end portions ZI are not completelysealed in the ordinary packaging machines which are generally used todayin bakeries and the like. Consequently, after the bread packages areplaced upon the shelves in stores, there is considerable loss ofmoisture at the ends of the package, unless some provision is made forpositively sealing the ends and retaining the wrapper in sealedrelation.

According to the present invention we provide a label or seal having acomposition or coating l2 upon its inner surface, as indicated in Figure2. The coating composition 12 provided on the seal is of such characterthat when it is applied to the ends of the package and pressedthereagainst by heat and pressure, the composition will fuse and unitewith the wax coating upon the wrapper 20, and thereby form a perfectseal or union therewith. A suitable coating composition for this purposeis a heat sensitive or thermoplastic waxrubber composition of thecharacter disclosed in Abrams Patents Nos. 2,054,112 and 2,054,115. Asatisfactory coating composition for use upon paper labels comprises amixture of paraflin wax and rubber, the rubber content being from 6 toabout 30% by weight of the composition, the mixture when used having aviscosity of at least 8,000 secs. (50 cc. measured on a Scottviscosimeter at 90 0.). We have found that when an end label or sealcoated with such composition is applied with the coated surface againstthe wax coating of the wrapper 20 by heat and pressure, the coatingcomposition will fuse with the wax, forming a unitary bond or seal whichadheres with great tenacity over its entire coated surface to the waxedsurface of the wrapper 20 and can be removed therefrom only withconsiderable difficulty.

Inasmuch as the packaging of commodities with waxed paper, especially inconnection with the packaging of bread, is usually carried out inmachinery supplied with heat sealing elements for sealing the ends ofthe package, our thermoplastic coated heat seal end label is especiallyadapted for use in conjunction with such machinery. For example, we maysupply our end seal labels in the form of a long roll of continuouslabels which are fed and cut off at the point where they are to beapplied to the end of the wrapped loaf of bread. The end seal may beapplied just after the wrapped loaf of bread has passed the finalfolding element in the bread wrapping machine. The residual heat presentin the wrapper at this point is sumcient to soften the coating l2 on theend seal, thereby serving to locate the end seal in place upon the endof the package and holding same in position for the subsequent action ofthe element in the machine for applying heat and pressure to the labelto seal samefirmly in place.

The coating I2 which we provide upon our label [0 may be made from anysuitable type of heat sensitive or thermoplastic compositions. Aspreviously stated, we may use suitable compositions comprising wax andrubber, or wax-like and rubber-like substances. We may, for example,employ a composition containing any type of suitable wax, such asparafiin wax, carnauba, beeswax, microcrystalline waxes, or amorphouswaxes and any synthetic wax-like substances. With these waxes we maycombine a film forming substance such as rubber, gutta percha, syntheticrubbers, polymers of isobutylene, resinous materials, Bakelite or otherphenol resins, glyptal resins, phthalic anhydride resins, ethyl orglyceryl esters, rosin or the like. These substances may be compoundedin any suitable proportion and in any known manner to produce a heatsensitive composition which may be coated upon our labels for use insealing same to waxed sheets and the like. The composition we use isheat sensitive upon application of heat thereto and is adapted to mergeor coalesce with ordinary wax coatings upon usual waxed papers used forpackaging purposes. Furthermore, our coated seals or labels are adaptedto be used upon any type of shellaced or coated papers which aredifficult to seal by the use of glues or similar adhesives which areavailable on the market today. v

Although the invention is; especially adapted for the sealing of ends ofwrapped packages, it is obvious that labels, stripes, bands and the likemay be similarly applied to any part of the body of the package. Forexample, as shown in Figure 1, we may apply labels or seals indicated bynumerals 30 and 3| to any body portion of the package. The seals 25 areapplied to the package in a similar manner as the end seals In by meansof heat and pressure, thereby causing same to tenaciously adhere to thewrapper. The end seals 25, as well as the seals 30 and 31, may beprovided with any desired ornamentation or printed matter II.

It is obvious that numerous departures and modifications of theinvention may be made without departing from the spirit of the inventionas defined in the appended claims.

We claim:

1. As an article of manufacture, a wrapped article comprising incombination, a Waxed wrapping material secured around the lateralsurfaces of the article and at the ends of the article, a supplementarysheet substantially overlying the ends .of the article and covering anyinterstices in the wrapper, and secured thereto by a thermoplasticcomposition comprising a waxy constituent and film forming constituent,the thermoplastic composition being coalesced with the waxed surface ofthe wrapping material.

2. A wrapped article comprising in combination, a waxed wrappingmaterial secured around the lateral surfaces of the article, overlappedend folds of the wrapper at the ends of the article, a supplementarysheet on the end folds of the wrapper, and secured thereto by awax-rubber composition on the supplementary sheet, said wax-rubbercomposition being substantially coalesced with the waxed surface coatingof the wrapping material.

3. As an article of manufacture, a wrapped article comprising, incombination, waxed wrapping material aroundthe lateral surfaces of thearticle, overlapped end folds of the wrapper at the ends of the article,and supplementary sheets on the wrapper and secured thereto by a heat 5sensitive composition comprising wax and resinous materials, thesupplementary sheets and the composition forming seals enclosing theinterstices of the end folds.

4. As an article of manufacture, a wrapped article comprising, incombination, a waxed wrap ping material completely enclosing saidarticle, and a supplementary sheet secured by heat and pressure tosaid'wrapping material by means of a heat sensitive thermoplasticwax-rubber compol5 sition.

5. A method of packaging articles provided with a waxed wrappingmaterial secured around the lateral surfaces of the article, and havingoverlapped folded end margins secured on the ends of the article, whichcomprises applying supplementary sheets having a thermoplastic heatsensitive coating composition thereon having a waxy constituent and afilm forming constituent onto the overlapped folds at the ends of thearticle, and applying heat and pressure to the supplementary sheets toadhere same to said wrapping material until the said coating compositionhas substantially coalesced with the wax coating upon said wrappingmaterial.

6. A method of packaging articles in waxed paper which comprisesapplying supplementary sheets having a heat sensitive coatingcomposition thereon having a waxy constituent and a firm formingconstituent into contact with the waxed surface of the waxed paper, andapplying suflicient heat and pressure to the supplementary sheets untilsaid composition has sufliciently coalesced with the wax coating on saidpaper to adhere to the paper.

7. In a method of packaging articles involving wrapping waxed paperaround the lateral surfaces of an article, folding the end margins ofthe wrapper into overlapping folds to cover the ends of the article,smoothing the ends with heat and pressure sufllcient to soften the waxand preliminarily stick the folds in place, the step of applyingsupplementary sheets provided with a waxrubber coating compositionthereon to the overlapping folds at the ends of the article while same 5is still warm, thereby securing said supplementary sheets into place,and applying sufilcient heat and pressure at opposite ends of thearticle until said coating composition has sufficiently coalesced withthe wax coating of said wrapper to seal the end folds of the wrappersecurely.

8. A method of packaging which comprises applying a label having athermoplastic heat sensitive coating composition comprising a waxyconstituent and a film forming constituent to a predetermined area ofthe overlapped portions of a waxed wrapper of a completely wrapped heatsealed package while the package is still warm and retains residual heatfrom the heat sealing operations whereby said label is definitely re- 55tained in position on said predetermined area and applying sufiicientheat and pressure to said positioned label until the coating compositionon said label has sufficiently coalesced with the wax coating of thewrapper to seal the package 70 securely.

MARSHALL H. SMITH. ROY A. NASH.

